aboutsummaryrefslogtreecommitdiff
path: root/block/ll_rw_blk.c
AgeCommit message (Collapse)Author
2007-06-15block: always requeue !fs requests at the frontTejun Heo
SCSI marks internal commands with REQ_PREEMPT and push it at the front of the request queue using blk_execute_rq(). When entering suspended or frozen state, SCSI devices are quiesced using scsi_device_quiesce(). In quiesced state, only REQ_PREEMPT requests are processed. This is how SCSI blocks other requests out while suspending and resuming. As all internal commands are pushed at the front of the queue, this usually works. Unfortunately, this interacts badly with ordered requeueing. To preserve request order on requeueing (due to busy device, active EH or other failures), requests are sorted according to ordered sequence on requeue if IO barrier is in progress. The following sequence deadlocks. 1. IO barrier sequence issues. 2. Suspend requested. Queue is quiesced with part or all of IO barrier sequence at the front. 3. During suspending or resuming, SCSI issues internal command which gets deferred and requeued for some reason. As the command is issued after the IO barrier in #1, ordered requeueing code puts the request after IO barrier sequence. 4. The device is ready to process requests again but still is in quiesced state and the first request of the queue isn't REQ_PREEMPT, so command processing is deadlocked - suspending/resuming waits for the issued request to complete while the request can't be processed till device is put back into running state by resuming. This can be fixed by always putting !fs requests at the front when requeueing. The following thread reports this deadlock. http://thread.gmane.org/gmane.linux.kernel/537473 Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: David Greaves <david@dgreaves.com> Acked-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-15ll_rw_blk: fix gcc 4.2 warning on current_io_context()Jens Axboe
current_io_context() is both static and exported with EXPORT_SYMBOL(). As there are no users outside of ll_rw_blk.c itself, just kill the export. Problem reported by Martin Michlmayr <tbm@cyrius.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11When stacked block devices are in-use (e.g. md or dm), the recursive callsNeil Brown
to generic_make_request can use up a lot of space, and we would rather they didn't. As generic_make_request is a void function, and as it is generally not expected that it will have any effect immediately, it is safe to delay any call to generic_make_request until there is sufficient stack space available. As ->bi_next is reserved for the driver to use, it can have no valid value when generic_make_request is called, and as __make_request implicitly assumes it will be NULL (ELEVATOR_BACK_MERGE fork of switch) we can be certain that all callers set it to NULL. We can therefore safely use bi_next to link pending requests together, providing we clear it before making the real call. So, we choose to allow each thread to only be active in one generic_make_request at a time. If a subsequent (recursive) call is made, the bio is linked into a per-thread list, and is handled when the active call completes. As the list of pending bios is per-thread, there are no locking issues to worry about. I say above that it is "safe to delay any call...". There are, however, some behaviours of a make_request_fn which would make it unsafe. These include any behaviour that assumes anything will have changed after a recursive call to generic_make_request. These could include: - waiting for that call to finish and call it's bi_end_io function. md use to sometimes do this (marking the superblock dirty before completing a write) but doesn't any more - inspecting the bio for fields that generic_make_request might change, such as bi_sector or bi_bdev. It is hard to see a good reason for this, and I don't think anyone actually does it. - inspecing the queue to see if, e.g. it is 'full' yet. Again, I think this is very unlikely to be useful, or to be done. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: <dm-devel@redhat.com> Alasdair G Kergon <agk@redhat.com> said: I can see nothing wrong with this in principle. For device-mapper at the moment though it's essential that, while the bio mappings may now get delayed, they still get processed in exactly the same order as they were passed to generic_make_request(). My main concern is whether the timing changes implicit in this patch will make the rare data-corrupting races in the existing snapshot code more likely. (I'm working on a fix for these races, but the unfinished patch is already several hundred lines long.) It would be helpful if some people on this mailing list would test this patch in various scenarios and report back. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-05-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits) sound: convert "sound" subdirectory to UTF-8 MAINTAINERS: Add cxacru website/mailing list include files: convert "include" subdirectory to UTF-8 general: convert "kernel" subdirectory to UTF-8 documentation: convert the Documentation directory to UTF-8 Convert the toplevel files CREDITS and MAINTAINERS to UTF-8. remove broken URLs from net drivers' output Magic number prefix consistency change to Documentation/magic-number.txt trivial: s/i_sem /i_mutex/ fix file specification in comments drivers/base/platform.c: fix small typo in doc misc doc and kconfig typos Remove obsolete fat_cvf help text Fix occurrences of "the the " Fix minor typoes in kernel/module.c Kconfig: Remove reference to external mqueue library Kconfig: A couple of grammatical fixes in arch/i386/Kconfig Correct comments in genrtc.c to refer to correct /proc file. Fix more "deprecated" spellos. Fix "deprecated" typoes. ... Fix trivial comment conflict in kernel/relay.c.
2007-05-09Add suspend-related notifications for CPU hotplugRafael J. Wysocki
Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09unify flush_work/flush_work_keventd and rename it to cancel_work_syncOleg Nesterov
flush_work(wq, work) doesn't need the first parameter, we can use cwq->wq (this was possible from the very beginnig, I missed this). So we can unify flush_work_keventd and flush_work. Also, rename flush_work() to cancel_work_sync() and fix all callers. Perhaps this is not the best name, but "flush_work" is really bad. (akpm: this is why the earlier patches bypassed maintainers) Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Jeff Garzik <jeff@garzik.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Tejun Heo <htejun@gmail.com> Cc: Auke Kok <auke-jan.h.kok@intel.com>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09kblockd: use flush_workAndrew Morton
Switch the kblockd flushing from a global flush to a more specific flush_work(). (akpm: bypassed maintainers, sorry. There are other patches which depend on this) Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Jens Axboe <axboe@suse.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09Fix occurrences of "the the "Michael Opdenacker
Signed-off-by: Michael Opdenacker <michael@free-electrons.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-05-08[PATCH] ll_rw_blk: fix missing bounce in blk_rq_map_kern()Mike Christie
I think we might just need the blk_map_kern users now. For the async execute I added the bounce code already and the block SG_IO has it atleady. I think the blk_map_kern bounce code got dropped because we thought the correct gfp_t would be passed in. But I think all we need is the patch below and all the paths are take care of. The patch is not tested. Patch was made against scsi-misc. The last place that is sending non sg commands may just be md/dm-emc.c but that is is just waiting on alasdair to take some patches that fix that and a bunch of junk in there including adding bounce support. If the patch below is ok though and dm-emc finally gets converted then it will have sg and bonce buffer support. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-05-05Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds
* master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (87 commits) [SCSI] fusion: fix domain validation loops [SCSI] qla2xxx: fix regression on sparc64 [SCSI] modalias for scsi devices [SCSI] sg: cap reserved_size values at max_sectors [SCSI] BusLogic: stop using check_region [SCSI] tgt: fix rdma transfer bugs [SCSI] aacraid: fix aacraid not finding device [SCSI] aacraid: Correct SMC products in aacraid.txt [SCSI] scsi_error.c: Add EH Start Unit retry [SCSI] aacraid: [Fastboot] Panics for AACRAID driver during 'insmod' for kexec test. [SCSI] ipr: Driver version to 2.3.2 [SCSI] ipr: Faster sg list fetch [SCSI] ipr: Return better qc_issue errors [SCSI] ipr: Disrupt device error [SCSI] ipr: Improve async error logging level control [SCSI] ipr: PCI unblock config access fix [SCSI] ipr: Fix for oops following SATA request sense [SCSI] ipr: Log error for SAS dual path switch [SCSI] ipr: Enable logging of debug error data for all devices [SCSI] ipr: Add new PCI-E IDs to device table ...
2007-04-30ll_rw_blk: add io_context private pointerJens Axboe
To be used by as/cfq as they see fit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-04-17[SCSI] sg: cap reserved_size values at max_sectorsAlan Stern
This patch (as857) modifies the SG_GET_RESERVED_SIZE and SG_SET_RESERVED_SIZE ioctls in the sg driver, capping the values at the device's request_queue's max_sectors value. This will permit cdrecord to obtain a legal value for the maximum transfer length, fixing Bugzilla #7026. The patch also caps the initial reserved_size value. There's no reason to have a reserved buffer larger than max_sectors, since it would be impossible to use the extra space. The corresponding ioctls in the block layer are modified similarly, and the initial value for the reserved_size is set as large as possible. This will effectively make it default to max_sectors. Note that the actual value is meaningless anyway, since block devices don't have a reserved buffer. Finally, the BLKSECTGET ioctl is added to sg, so that there will be a uniform way for users to determine the actual max_sectors value for any raw SCSI transport. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Douglas Gilbert <dougg@torque.net> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2007-03-27block: blk_max_pfn is somtimes wrongVasily Tarasov
There is a small problem in handling page bounce. At the moment blk_max_pfn equals max_pfn, which is in fact not maximum possible _number_ of a page frame, but the _amount_ of page frames. For example for the 32bit x86 node with 4Gb RAM, max_pfn = 0x100000, but not 0xFFFF. request_queue structure has a member q->bounce_pfn and queue needs bounce pages for the pages _above_ this limit. This routine is handled by blk_queue_bounce(), where the following check is produced: if (q->bounce_pfn >= blk_max_pfn) return; Assume, that a driver has set q->bounce_pfn to 0xFFFF, but blk_max_pfn equals 0x10000. In such situation the check above fails and for each bio we always fall down for iterating over pages tied to the bio. I want to notice, that for quite a big range of device drivers (ide, md, ...) such problem doesn't happen because they use BLK_BOUNCE_ANY for bounce_pfn. BLK_BOUNCE_ANY is defined as blk_max_pfn << PAGE_SHIFT, and then the check above doesn't fail. But for other drivers, which obtain reuired value from drivers, it fails. For example sata_nv uses ATA_DMA_MASK or dev->dma_mask. I propose to use (max_pfn - 1) for blk_max_pfn. And the same for blk_max_low_pfn. The patch also cleanses some checks related with bounce_pfn. Signed-off-by: Vasily Tarasov <vtaras@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-02-09[PATCH] md: fix various bugs with aligned reads in RAID5Neil Brown
It is possible for raid5 to be sent a bio that is too big for an underlying device. So if it is a READ that we pass stright down to a device, it will fail and confuse RAID5. So in 'chunk_aligned_read' we check that the bio fits within the parameters for the target device and if it doesn't fit, fall back on reading through the stripe cache and making lots of one-page requests. Note that this is the earliest time we can check against the device because earlier we don't have a lock on the device, so it could change underneath us. Also, the code for handling a retry through the cache when a read fails has not been tested and was badly broken. This patch fixes that code. Signed-off-by: Neil Brown <neilb@suse.de> Cc: "Kai" <epimetreus@fastmail.fm> Cc: <stable@suse.de> Cc: <org@suse.de> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-22[PATCH] fix kernel-doc warnings in 2.6.20-rc1Randy Dunlap
Fix kernel-doc warnings in 2.6.20-rc1. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-19[PATCH] Fixup blk_rq_unmap_user() APIJens Axboe
The blk_rq_unmap_user() API is not very nice. It expects the caller to know that rq->bio has to be reset to the original bio, and it will silently do nothing if that is not done. Instead make it explicit that we need to pass in the first bio, by expecting a bio argument. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-19[PATCH] __blk_rq_unmap_user() fails to return errorJens Axboe
If the bio is user copied, the copy back could return -EFAULT. Make sure we return any error seen during unmapping. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-19[PATCH] __blk_rq_map_user() doesn't need to grab the queue_lockJens Axboe
It was for driver private back_merge_fn hooks, but they don't exist anymore. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-19[PATCH] Remove queue merging hooksJens Axboe
We have full flexibility of merging parameters now, so we can remove the hooks that define back/front/request merge strategies. Nobody is using them anymore. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-19[PATCH] ->nr_sectors and ->hard_nr_sectors are not used for BLOCK_PC requestsJens Axboe
It's a file system thing, for block requests the only size used in the io paths is ->data_len as it is in bytes, not sectors. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-13[PATCH] Propagate down request sync flagJens Axboe
We need to do this, otherwise the io schedulers don't get access to the sync flag. Then they cannot tell the difference between a regular write and an O_DIRECT write, which can cause a performance loss. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-12[PATCH] remove blk_queue_activity_fnBoaz Harrosh
While working on bidi support at struct request level I have found that blk_queue_activity_fn is actually never used. The only user is in ide-probe.c with this code: /* enable led activity for disk drives only */ if (drive->media == ide_disk && hwif->led_act) blk_queue_activity_fn(q, hwif->led_act, drive); And led_act is never initialized anywhere. (Looking back at older kernels it was used in the PPC arch, but was removed around 2.6.18) Unless it is all for future use off course. (this patch is against linux-2.6-block.git as off 2006/12/4) Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-12-10[PATCH] io-accounting: read accountingAndrew Morton
Wire up read accounting for block devices, within submit_bio(). Cc: Jay Lan <jlan@sgi.com> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Chris Sturtivant <csturtiv@sgi.com> Cc: Tony Ernst <tee@sgi.com> Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net> Cc: David Wright <daw@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] fault-injection capability for disk IOAkinobu Mita
This patch provides fault-injection capability for disk IO. Boot option: fail_make_request=<probability>,<interval>,<space>,<times> <interval> -- specifies the interval of failures. <probability> -- specifies how often it should fail in percent. <space> -- specifies the size of free space where disk IO can be issued safely in bytes. <times> -- specifies how many times failures may happen at most. Debugfs: /debug/fail_make_request/interval /debug/fail_make_request/probability /debug/fail_make_request/specifies /debug/fail_make_request/times Example: fail_make_request=10,100,0,-1 echo 1 > /sys/blocks/hda/hda1/make-it-fail generic_make_request() on /dev/hda1 fails once per 10 times. Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] hotplug CPU: clean up hotcpu_notifier() useIngo Molnar
There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn, prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus generating compiler warnings of unused symbols, hence forcing people to add #ifdefs. the compiler can skip truly unused functions just fine: text data bss dec hex filename 1624412 728710 3674856 6027978 5bfaca vmlinux.before 1624412 728710 3674856 6027978 5bfaca vmlinux.after [akpm@osdl.org: topology.c fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] slab: remove kmem_cache_tChristoph Lameter
Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-05Merge branch 'master' of ↵David Howells
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: drivers/infiniband/core/iwcm.c drivers/net/chelsio/cxgb2.c drivers/net/wireless/bcm43xx/bcm43xx_main.c drivers/net/wireless/prism54/islpci_eth.c drivers/usb/core/hub.h drivers/usb/input/hid-core.c net/core/netpoll.c Fix up merge failures with Linus's head and fix new compilation failures. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-12-01[PATCH] block: support larger block pc requestsMike Christie
This patch modifies blk_rq_map/unmap_user() and the cdrom and scsi_ioctl.c users so that it supports requests larger than bio by chaining them together. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-11-22WorkStruct: Pass the work_struct pointer instead of context dataDavid Howells
Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-03[PATCH] tidy "md: check bio address after mapping through partitions"Andrew Morton
Neil's xterms are too wide. Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-31[PATCH] md: check bio address after mapping through partitions.NeilBrown
Partitions are not limited to live within a device. So we should range check after partition mapping. Note that 'maxsector' was being used for two different things. I have split off the second usage into 'old_sector' so that maxsector can be still be used for it's primary usage later in the function. Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Neil Brown <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20[PATCH] separate bdi congestion functions from queue congestion functionsAndrew Morton
Separate out the concept of "queue congestion" from "backing-dev congestion". Congestion is a backing-dev concept, not a queue concept. The blk_* congestion functions are retained, as wrappers around the core backing-dev congestion functions. This proper layering is needed so that NFS can cleanly use the congestion functions, and so that CONFIG_BLOCK=n actually links. Cc: "Thomas Maier" <balagi@justmail.de> Cc: "Jens Axboe" <jens.axboe@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: David Howells <dhowells@redhat.com> Cc: Peter Osterlund <petero2@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20[PATCH] export clear_queue_congested and set_queue_congestedThomas Maier
Export the clear_queue_congested() and set_queue_congested() functions located in ll_rw_blk.c The functions are renamed to blk_clear_queue_congested() and blk_set_queue_congested(). (needed in the pktcdvd driver's bio write congestion control) Signed-off-by: Thomas Maier <balagi@justmail.de> Cc: Peter Osterlund <petero2@telia.com> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04[PATCH] helper function for retrieving scsi_cmd given host based block layer tagDavid C Somayajulu
This was necessitated by the need for a function to get back to a scsi_cmnd, when an hba the posts its (corresponding) completion interrupt with a block layer tag as its reference. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: David Somayajulu <david.somayajulu@qlogic.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-09-30[PATCH] blk_queue_start_tag() shared map race fixJens Axboe
If we share the tag map between two or more queues, then we cannot use __set_bit() to set the bit. In fact we need to make sure we atomically acquire this tag, so loop using test_and_set_bit() to protect from that. Noticed by Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30[PATCH] exit_io_context: don't disable irqsOleg Nesterov
We don't need to disable irqs to clear current->io_context, it is protected by ->alloc_lock. Even IF it was possible to submit I/O from IRQ on behalf of current this irq_disable() can't help: current_io_context() will re-instantiate ->io_context after irq_enable(). We don't need task_lock() or local_irq_disable() to clear ioc->task. This can't prevent other CPUs from playing with our io_context anyway. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30[PATCH] Allow file systems to differentiate between data and meta readsJens Axboe
We can use this information for making more intelligent priority decisions, and it will also be useful for blktrace. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] ll_rw_blk: allow more flexibility for read_ahead_kb storeJens Axboe
It can make sense to set read-ahead larger than a single request. We should not be enforcing such policy on the user. Additionally, using the BLKRASET ioctl doesn't impose such a restriction. So additionally we now expose identical behaviour through the two. Issue also reported by Anton <cbou@mail.ru> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Add blk_start_queueing() helperJens Axboe
CFQ implements this on its own now, but it's really block layer knowledge. Tells a device queue to start dispatching requests to the driver, taking care to unplug if needed. Also fixes the issue where as/cfq will invoke a stopped queue, which we really don't want. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Make sure all block/io scheduler setups are node awareJens Axboe
Some were kmalloc_node(), some were still kmalloc(). Change them all to kmalloc_node(). Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Audit block layer inlinesJens Axboe
Kill a few inlines that bring in too much code to more than one location Shrinks kernel text by about 300 bytes on 32-bit x86. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] cfq-iosched: kill cfq_exit_lockJens Axboe
cfq_exit_lock is protecting two things now: - The per-ioc rbtree of cfq_io_contexts - The per-cfqd linked list of cfq_io_contexts The per-cfqd linked list can be protected by the queue lock, as it is (by definition) per cfqd as the queue lock is. The per-ioc rbtree is mainly used and updated by the process itself only. The only outside use is the io priority changing. If we move the priority changing to not browsing the rbtree, we can remove any locking from the rbtree updates and lookup completely. Let the sys_ioprio syscall just mark processes as having the iopriority changed and lazily update the private cfq io contexts the next time io is queued, and we can remove this locking as well. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] ll_rw_blk: cleanup __make_request()Jens Axboe
- Don't assign variables that are only used once. - Kill spin_lock() prefetching, it's opportunistic at best. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Drop useless bio passing in may_queue/set_request APIJens Axboe
It's not needed for anything, so kill the bio passing. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Remove ->rq_status from struct requestJens Axboe
After Christophs SCSI change, the only usage left is RQ_ACTIVE and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing the request, so any check for RQ_INACTIVE in a driver is a bug and indicates use-after-free. So kill/clean the remaining users, straight forward. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Remove struct request_list from struct requestJens Axboe
It is always identical to &q->rq, and we only use it for detecting whether this request came out of our mempool or not. So replace it with an additional ->flags bit flag. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Remove ->waiting member from struct requestJens Axboe
As the comments indicates in blkdev.h, we can fold it into ->end_io_data usage as that is really what ->waiting is. Fixup the users of blk_end_sync_rq(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30[PATCH] elevator: abstract out the rbtree sort handlingJens Axboe
The rbtree sort/lookup/reposition logic is mostly duplicated in cfq/deadline/as, so move it to the elevator core. The io schedulers still provide the actual rb root, as we don't want to impose any sort of specific handling on the schedulers. Introduce the helpers and rb_node in struct request to help migrate the IO schedulers. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] elevator: move the backmerging logic into the elevator coreJens Axboe
Right now, every IO scheduler implements its own backmerging (except for noop, which does no merging). That results in duplicated code for essentially the same operation, which is never a good thing. This patch moves the backmerging out of the io schedulers and into the elevator core. We save 1.6kb of text and as a bonus get backmerging for noop as well. Win-win! Signed-off-by: Jens Axboe <axboe@suse.de>
2006-09-30[PATCH] Split struct request ->flags into two partsJens Axboe
Right now ->flags is a bit of a mess: some are request types, and others are just modifiers. Clean this up by splitting it into ->cmd_type and ->cmd_flags. This allows introduction of generic Linux block message types, useful for sending generic Linux commands to block devices. Signed-off-by: Jens Axboe <axboe@suse.de>